EARLIER ATTAINMENT OF TARGET TEMPERATURE DURING THERAPEUTIC HYPOTHERMIA MAY NOT BE ASSOCIATED WITH BETTER OUTCOME IN A MIXED POPULATION OF COMATOUS SURVIVORS OF CARDIAC ARREST

Introduction: Recent guidelines recommend  the use of induced therapeutic hypothermia (TH) in survivors of out-of hospital cardiac arrest caused by ventricle fibrillation. Recently, two randomized trials on post ROSC (return of spontaneous circulation) hypothermia failed to prove the benefit of prehospital cooling and inhospital target temperature management of 33°C over 36°C. Moreover, few reports suggested, that early attainment of target temperature might be associated with worse outcome. Therefore, we aimed to evaluate the significance of early target temperature (≤ 34°C ) attainment  in a mixed population  of comatous survivors of cardiac arrest treated by TH. 
Methods: data were analyzed based on prospective registry of cardiac arrest patients with succesful ROSC.
Results: During the study period from Nov 2002 to Aug 2013, 207 adult patients were enrolled into the registry. TH was initiated in 179 (86%) patients, target temperature of ≤ 34°C was reached in 166 (93%) patients. Overall, 89 (43%) patients survived to 180 days, 79 (90%) of them with CPC 1 or 2. In terms of survival and favorable/unfavorable outcome in succesfully cooled patients, 180 days survivors and patients with favorable outcome had longer times of cooling to reach target temperature in comparison to non-survivors and patients with unfavorable outcome (195 [120, 345]  min vs. 125 [60-240] min, p = 0,012 and 195.0 [112.5 – 345.0] min vs. 145.0 [60.0 – 240.0] min, p = 0.038, respectively). For both these groups differences were not detectable for time delay to initiation of TH and for temperature on admission.
Conclusion: Our study provides an evidence that earlier attainment of target temperature of ≤ 34°C during TH in post ROSC cardiac arrest patients may not be associated with better outcome.